Spring Garden Advice
MARCH
Weeding
Start with a good clear out, hoe your vegetable plot and hand-weed herbaceous borders. Remove and burn all perennial weeds.
Cut back
Cut back last year’s stems of salix and cornus grown for winter colour almost to ground level.
Planting
Plant container grown herbaceous and woodland plants. Also plant container grown trees and shrubs. Bare-rooted roses can be planted as soon as ground is neither frozen or water logged. It’s a good time to grow perennials from seed and also to plant young plants such as sweet peas for summer flowering as soon as the soil conditions are favorable. Plant out spring bedding into pots to create a bright display, and also lily of the valley crowns that will thrive in most areas. Move and plant snowdrops as they finish flowering (see double-up section below).
Start an aromatic garden
Use fragrant plants such as lavenders, salvias, origanums, thyme and atemisias. These plants will thrive in the sunniest part of your garden and the honey bees will be delighted.
Divide Autumn-flowering Perennials
To ensure they flower later in the year divide sedums, kniphonias and phlox.
Double-up
Divide clump-forming plants left over from autumn, including less hardy types such as peonies, as soon as new growth begins. Lift, divide and replant clumps of snowdrops and aconites in the later part of the month.
Lawn care
Rake over the lawn and repair damaged edges with squares of turf and re-sow bare areas of lawn with grass seed. Apply a Spring/Summer general fertilizer to give the lawn a boost and a growth revival. If the weather is fair then the lawn can be given its first cut of the season, set the blade to around 1 inch.
Patios, Paths and Driveways
Sweep and then power wash all paths, patios and driveways taking care not to damage any surrounding lawn or plants. If the stone has an algal coverage this can be removed using a firm brush that has been dipped in a dilute solution of potassium permanganate.
In the Vegetable Plot
Hoe your vegetable plot and then sow loose leaf lettuce and vegetables such as leeks, spinach, beetroot carrots, broad beans and early peas. Plant asparagus crowns in a specially made asparagus bed, you will be able to cut your first spears in two season’s time. In the last week of March plant early varieties of potato.
APRIL
Lawn care
Check you are happy with the repairs from the previous month, correcting as necessary. Apply a selective weed killer and then mow at least once a week, gradually lowering the blades to about ½ in.
Weeding
Keep hoeing to prevent weeds from seeding and stealing nutrients from other plants.
Deadhead Daffodils
Deadhead daffodils, narcissi and other late-winter flowering plants. As each flower fades remove the head, however leave the green foliage for at least 6 weeks to replenish the bulb.
Stake Herbaceous Borders
Use iron supports, hazel and willow to stake herbaceous plants. The new shoots will soon be coming strong. Stake tall-growing plants such as delphiniums and michaelmas daisies at an early stage of growth.
Planting
Towards the end of April start dahlia tubers off in containers and then plant them out while they are still young. It’s a good idea to support and stake as you go. Plant bare-rooted evergreens as long as the ground is moist. Only plant deciduous trees and shrubs if they are pot-grown. Containerised roses can also be planted out, provided there is no frost and the ground conditions are correct. Make a scree garden for alpines and drought-tolerant plants now and they will quickly establish themselves. Plant aquatic plants, such as water lilies only if the weather is mild otherwise leave this job until late spring. Sowing hardy annual seeds in open garden when soil conditions permit, late sowing could ruin the flower garden display for early summer. If cold winds persist shelter newly planted shrubs with screens.
Pruning
Prune any spring or winter flowering shrubs after flowering for example prune forsythia as soon as the flowers begin to fade. If flower heads on Hydrangeas were kept for winter interest now is the time to prune them. Layer camellias, rhododendrons and other acid-loving evergreens. Prune hardy fuchsias, buddleias and other shrubs which flower on current season’s growth to two or three buds from base. Remember that hamamelis and all daphnes need very little or no pruning.
Trim Formal Hedges
As soon as the chance of heavy frost has passed you can begin to trim formal hedges and box that is containerised. The next time for clipping will be in August and this early trim will instantly neaten up your garden by re-establishing the sharp lines and curves.
Sweet Peas
Create tripods or frames using sticks and string before planting out your sweet pea plants. Water them often with a can of warm water.
In the Vegetable Plot
Now that the soil is just warming up, you can sow parsnips and parsley. They will germinate in one month’s time. Sow all main crop potatoes now for a harvest in late September. Main crop leeks can also be planted outdoors into shallow drills.
MAY
General Maintenance
Continue the general maintenance routine of hoeing, sowing, thinning and planting. As soon as the daffodils are finished feed them with a fertilizer high in potash, leave the foliage for 6 weeks before cutting back to the bulbs can be built up for next year. Dead head rhododendrons and azaleas to encourage the formation of next year’s blooms. When the soil is moist, spread a mulch of pulverised bark, compost or well-rotted manure. Lightly dress all trees and shrubs with a high nitrogen general fertiliser. Mulch all herbaceous plants with well-rotted manure or garden compost. When weather is warm and humid slugs will flourish, so take measures to protect plants from slugs. Remove suckers, shoots rising from ground level, directly from the roots from roses, lilacs and other shrubs.
Watering
May is a critical growth period so if the month is dry plants need to be watered copiously given at least 1 gallon per square yard at each watering.
Planting
Plant out shrubs that are tender when young, such as choisya, fuchsia and hydrangea.
Keep newly planted trees and shrubs moist at the roots during dry periods. Spray foliage with water from time to time. Plant Amaryllis belladonna as soon as the bulbs become available. Plant half-hardy bulbs such as crinum in sheltered positions. Dahlia tubers can be planted in well-prepared ground that has been enriched beforehand with well-rotted manure or garden compost.
Rose Garden
Deal with any signs of aphid infestation immediately. It is usually best to spray them with insecticide first thing in the morning or alternatively in the evening.
Container Plants
Plant out the displays for your planters and urns and water regularly. Keep an eye on your containers, should you notice they wilt suddenly this could be vine weevils and you will need to investigate.
In the pond
Thin out overgrown clumps of water lilies and remove some of the larger leaves.
Cutting Down and Trimming
Now is the time to cut down tulip bulbs to the lowest leaf or dig out completely, saving for next year. These gaps are then ready to be replaced with summer bedding plants.
Trim back spreading alpine, such as aubrietia and arabis, 2-3in from the base when they have finished flowering.
Remove growing tips of tall perennials such as asters and solidago, and thin out weak shoots from the centre of overcrowded plants to promote sturdy growth and better flowers.
Lawn Care
Mow your lawn regularly, trimming the edges neatly after every cut. Start a programme for feeding it too. Apply selective weed-killer, one that is more effective when weeds are growing strongly, or alternatively cut out weeds with a knife. Now is a good time to start a compost heap using the first lawn cuttings of the season.
In the Vegetable Garden
Carry on sowing herbs, lettuce, carrots, peas, spinach and any other preferred vegetables.
Plant out outdoor tomatoes, courgettes and squash towards the end of the month. Containers can be filled with chillies, tomatoes, spinach and lettuce. Prevent potato tubers from turning green by covering with mounds of soil.
